Valve bag



VALVE BAG Filed Jan. 27, 1934 ATTOR'N EY5 Patented Dec. 31, 1935 UNITED STATES PATENT OFFICE VALVE BAG Application January 2'7, 1934, Serial No. 708,576

1 In Great Britain February 25, 1933 3 Claims. (01. 150-9) This invention relates to the formation of valve bags, whether of paper or other suitable material, which are provided with'an opening, self closing from the inside, into which may be introduced a filling spout through which the fluent material with which the bag is to be filled, such as Portland cement, for example, may be directed into the bag. Heretofore, in the formation of such bagsit has been necessary to give to that portion of the bag, which forms the underside of the opening and is pressed up against the end of the bag by the material with which the bag is filled, a considerable length in order that such portion or flap may not be forced outward sufficiently to make an opening through which the material with which the bag is filled may escape. As will be understood by those familiar with the making of valve bags every inch added to the length of the under flap of the valve means a corresponding increase in the length of the blank of which the bag is formed, and when two or three or even more inches are added to the under flap of the valve in order to guard against such accidental opening and leakage of material and when such bags are manufactured by the thousands it will be understood that the length of material required to be provided in order that such accidental opening may be prevented is a substantial element in the cost of production of the bags. In the endeavor to reduce the cost of manufacture of valve bags, particularly by reducing the length of material heretofore found to be necessary in order to prevent the turning outward through the valve of the lower flap of the valve, it has been found in the development of the present invention that such undesirable turning outward of the lower flap of the valve can be prevented, without in any way interfering with the ready introduction of the filling spout into the valve and without increasing the cost by an amount which is comparable with the cost of the material heretofore necessary to make the under flap of the valve sufficiently long to prevent it from being turned out, by securing the end memher which is turned in to form the under flap of the valve to one or both of the side members which form the end of the bag, as by stitching, as with thread, or wire, or a wire staple, or a rivet, or an adhesive. In some cases the securing of the valve fiap to one of the side members of the end of the bag may be found sufiicient, but for greater security it may be desirable to secure the valve flap to both of the side members. Experience has shown that such securing of the valve flap to the side membe s of the bag end does not interfere with the ready introduction of the filling spout into the valve or with the proper closing of the valve by pressure from within when the bag is filled and permits the prevention of the turning outward of the valve flap to be accomplished with a length of material which is only a portion of the length heretofore found necessary.

The invention will be more fully explained hereinafter with reference to the accompanying drawing in which it is illustrated and in which Figures 1-8 illustrate the application of the invention to one form of bag while Figures 9-12 illustrate the application of the invention to another form of bag.

In the drawing:

Figure 1 is an outline view in elevation of the upper right hand corner of a blank which may be used in the formation of the improved bag.

Figure 2 is a view of the same in perspective showing that the blank is formed with two walls which are in contact when the bag is shipped fiat and are separated when the bag is filled.

Figure 3 is a view in perspective showing the two opposite side members of the bag end at right agles to the body of the bag and the end member turned in against the two side members to form the lower flap of the valve and secured to both of such side members.

Figure 4 is a view in elevation showing one of. the side members turned down against the body of the bag, and the other side member and the end member also in a vertical plane.

Figure 5 is a view in elevation showing one of the side members folded down upon the other.

Figure 6 is a similar view showing the second side member turned up against the first side member, all the members being in vertical planes.

Figure '7 is a view in perspective illustrating the construction of the completed bag with the side members and the valve flap at right angles to the body of the bag.

Figure 8 is a view in perspective, and partly broken away, showing the body of the bag distended and the side members at right angles to the body.. 7

Referring first to the formation of the bag shown in Figures 1-8 the two side walls a, a are folded along the vertical line b, b which forms, when viewed as seen in the several figures of the drawing, the right hand vertical end or edge of the completed bag. Those portions of the side walls of the bag which are to form the side members 0, c of the bag end are folded outwardly, as shown in Figure 3, from a. common meeting line 0 and the end member d is folded in against the side members to form the under valve flap portion d of the end member (2 as from the dot and dash line 7, in Figures 3 and 4, to the dot and dash line f in the same figures, being folded on the lines I), d and b, 11 The formation of the bag end is then continued by folding the side members 0, 0 over one upon an-- other, as shown in Figures 5 and 6, all parts being then substantially or nearly in the plane of. a the bag walls a, a in which condition the bag is usually shipped, and the valve flap or end member at is secured, outside of the portion d to that one of the side members a, c which is first turned in, by any suitable means, a wire stitch ing or staple being indicated at e by way of example. In order that the valve may be effective in preventing escape of material from the bag when filled, without giving it such length as has heretofore been deemed necessary, it is necessary that the side member first turned in be secured to the end member outside of the valve flap portion d Otherwise, when the bag is filled, the valve flap portion would not be restrained from displacement with respect to that side member with the consequence that escape of material would be permitted. As a practical result the whole flap portion would be forced out from the bag.

When the bag is to be filled the side members c, c and the end member d are turned into positions at right angles to the body of the bag and the bag is then in readiness to be slipped upon the filling spout, the under valve portion d of the end member d being slightly depressed and the side members 0, c being slightly raised to permit the spout to be introduced.

In this construction even when the valve flap is secured to only one of the side members of the bag end it is found that sufficient resistance is offered by the valve flap portion d of the end member :1 to the pressure of the material in the bag to prevent the valve flap from being forced outward so as to make an opening through which the contents of the bag may escape. For some purposes, however, as in the bagging of cement which is very fluent and heavy, it may be desirable to secure the valve flap to both of the side members of the bag end as represented in Figures 3-8 of the drawing.

The securing of the valve flap to one or both of the end side members is preferably effected after the folding has been completed and the bag is removed from the machine on which the folding is efiected.

It will be understood that various changes in details of construction and arrangement may be made to suit diiferent forms of valve bags, and that the invention is not limited, except as pointed out in the accompanying claims.

I claim as my invention:

1. A valve bag having bag end side members both folded outward from a common line and each folded inward toward the other and overlapped and an end member turned upon the side members and folded inward with the side members to form an under valve flap portion, and means applied closely adjacent to the line on which one of the side members is first turned in to secure the end member outside the valve flap portion at one side to that side member of the bag which is first turned in.

2. A valve bag having bag end side members turned outward in opposite directions from the planes of the side walls and folded inward toward each other and overlapped, and an end member turned in upon the side members and folded inward with the side members to form a valve flap portion, the end member being secured closely adjacent to the line on which one of the side members is first turned in and outside of the valve fiap portion to that side member of the bag which is first turned in.

3. A valve bag having bag end side members turned outward in opposite directions from the plane of the side walls and folded inward toward each other and overlapped, and an end member turned in upon the side members and folded inward with the side members to form a valve flap member, the end member being secured clo'sely adjacent to the line on which the said members are turned in and outside of the valve flap portion to both of said side members.

MIKAEL VOGEL-J ORGEN SEN, 

